The present invention relates, in general, to display systems. More specifically, the present invention is a method and system for providing artifact-free transitions between dual display controllers.
In a typical display system, a display controller obtains an input signal from a processor such as a Central Processing Unit (CPU). The display controller processes the input signal and provides an output signal. Thereafter, the output signal drives a display device of the display system.
In a dual-display controller system, the two display controllers are usually referred as primary and secondary display controllers. The primary and secondary display controllers are individually controlled by the processor. The display device can be controlled by any of the two display controllers. The control of the display device can be switched between the primary and the secondary display controllers. However, switching the control of the display device between the primary and the secondary display controllers has to be synchronized to avoid any artifact on the display device.
There are various techniques for synchronizing the primary and secondary display controllers. In a conventional technique, known as ‘Genlock’, the primary and the secondary display controllers work simultaneously. Additionally, the output from the primary and the secondary display controllers is merged to form an image on the display device. However, this merging and synchronizing of outputs require expensive and complicated electronic systems.
According to other conventional techniques, synchronization of the primary and secondary display controllers is realized by transferring the display frames of the primary display controller to the secondary display controller. The display frames can be modified by either of the display controllers. This modification and transfer of display frames requires continual intervention of the processor.
However, conventional techniques suffer from one or more of the following shortcomings. These techniques require both the display controllers to run simultaneously and therefore, continual intervention of the processor is required. Consequently, power is used incessantly by the display system. There are some other conventional techniques that do not require continual intervention of the processor but are complex and expensive.
In light of the foregoing discussion, there is a need for a method that can synchronize the primary and the secondary display controllers and overcome the above-mentioned shortcomings. Further, there is a need for a method that requires minimal or no intervention of the processor. There is also a need for a method that can provide an artifact-free transition between the primary and secondary display controllers. Additionally, there is a need for a method that does not require expensive hardware and is ideal for use in a cost-sensitive display system. Moreover, there is a need for a method and system that consumes less power.